Second-order discontinuous Galerkin flood model: Comparison with industry-standard finite volume models

Finite volume (FV) numerical solvers of the two-dimensional shallow water equations are core to industry-standard flood models. The second-order Discontinuous Galerkin (DG2) alternative, although a viable way forward improve current FV-based models, is yet under-studied and rarely used support modelling applications. This paper systematically explores compares predictive properties robust DG2 model those prominent industrial To identify simplest most efficient configuration suitable for inundation modelling, two variants – with without local slope limiting considered. conservation compared first-order FV (FV1) (FV2) counterparts. then tested over five realistic flooding scenarios, recommended by UK Environment Agency validate 2D capabilities, while comparing their performance against that four commercial models (i.e. TUFLOW-FV1, TUFLOW-FV2, TUFLOW-HPC Infoworks ICM). Results reveal variant (DG2-NL) capable simulate shockless flows featured in wide range DG2-NL shows closer predictions outputs at twice-coarser spatial resolution, can run twice faster produce more informative hydrograph small-scale transients long-range simulations, even when sampling far away from source.